The solar energy is very important substitute energy and many of generating devices using solar energy are successfully developed and applied to different types of industries. From the approximately past several ten years ago, great attention has been paid to silicon solar cells (photoelectric conversion element) as a power source which is harmless to the environment. A solar cell basically includes a substrate provided a lower electrode thereon, a conductive film, a light-absorption layer, a window layer provided an upper electrode thereon, and a buffer layer formed between the light-absorption layer and the window layer. Photovoltaic cells for producing electricity from sunlight have been disclosed by U.S. Pat. No. 2,530,408, U.S. Pat. No. 5,350,644 and U.S. Pat. No. 7,737,356, and reference: Y Uchida et al., “Conversion Efficiency of Large Area a-Si:H Solar Cell”, Conference Proceedings, Fifteenth IEEE Photovoltaic Specialist Conference, Florida (1981), pp. 922-927.
As well known, conventional solar cells are such as crystalline silicon solar cell (referring to U.S. Pat. No. 7,666,706 and U.S. Pat. No. 7,029,644), polysilicon solar cell employing polycrystalline silicon (single crystal silicon), amorphous silicon solar cell (referring to U.S. Pat. No. 6,307,146, U.S. Pat. No. 5,693,745 and U.S. Pat. No. 5,334,259, and reference: C. R. Wronski, “The Dependence of Solar Cell Characteristics on the _Electronic Properties of Discharge Produced, Hydrogenated Amorphous _Silicon”, Conf. Record, 13th IEEE Photovoltaic Specialists Conf., _June 1978, pp. 744-750.), copper indium selenide solar cell, and compound semiconductor solar cell. These solar cells have already been practically used in industrial and household applications. Some of these solar cells employing silicon require high manufacturing cost. Recently, thin-film crystalline silicon solar cell, compound semiconductor solar cell, and amorphous silicon solar cell are studied and developed extensively as they can be formed by low cost.
The present invention intends to provide an application of the solar cell module which is used for illumination. The application can be used for the street lights, garden lights or wall lights. The conventional illumination devices generally comprise a reflection disk, solar cells and illumination members. Nevertheless, all of the components are installed separately, the illumination members cannot be rotated with the solar cells so that they cannot be located at the focus of the reflection disk. In other words, at least one of the two components is not located at the focus of the reflection disk so that the efficiency will be low and the illumination members cannot provide sufficient illumination features.